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Title: Resonant tunneling with high peak to valley current ratio in SiO{sub 2}/nc-Si/SiO{sub 2} multi-layers at room temperature

We have investigated carrier transport in SiO{sub 2}/nc-Si/SiO{sub 2} multi-layers by room temperature current-voltage measurements. Resonant tunneling signatures accompanied by current peaks are observed. Carrier transport in the multi-layers were analyzed by plots of ln(I/V{sup 2}) as a function of 1/V and ln(I) as a function of V{sup 1/2}. Results suggest that besides films quality, nc-Si and barrier sub-layer thicknesses are important parameters that restrict carrier transport. When thicknesses are both small, direct tunneling dominates carrier transport, resonant tunneling occurs only at certain voltages and multi-resonant tunneling related current peaks can be observed but with peak to valley current ratio (PVCR) values smaller than 1.5. When barrier thickness is increased, trap-related and even high field related tunneling is excited, causing that multi-current peaks cannot be observed clearly, only one current peak with higher PVCR value of 7.7 can be observed. While if the thickness of nc-Si is large enough, quantum confinement is not so strong, a broad current peak with PVCR value as high as 60 can be measured, which may be due to small energy difference between the splitting energy levels in the quantum dots of nc-Si. Size distribution in a wide range may cause un-controllability of the peakmore » voltages.« less
Authors:
 [1] ;  [2] ; ;  [3] ; ;  [1]
  1. Department of Physics, Nanjing National Laboratory of Microstructures and Key Laboratory of Advanced Photonic and Electronic, materials, Nanjing University, Nanjing 210093 (China)
  2. (China)
  3. Nanjing University of posts and Telecommunications, Nanjing 210046 (China)
Publication Date:
OSTI Identifier:
22275665
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 4; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 77 NANOSCIENCE AND NANOTECHNOLOGY; CHARGE CARRIERS; ELECTRIC CONDUCTIVITY; ELECTRIC CURRENTS; ELECTRIC POTENTIAL; ENERGY LEVELS; INTERFACES; LAYERS; QUANTUM DOTS; SILICON; SILICON OXIDES; TEMPERATURE RANGE 0273-0400 K; THICKNESS; THIN FILMS; TRAPS; TUNNEL EFFECT